The operation principle of electromagnetic type input technology is performed by a circuit board with a plurality of antennas or sensor coils arranged along x and y axial directions and an electromagnetic pen which can emit electromagnetic signals. The sensing plane of an electromagnetic input apparatus includes a plurality of antennas or sensor coils. The antennas or sensor coils are arranged under a work surface or a display panel of the electromagnetic input apparatus. The coordinates of the electromagnetic pen are obtained through the transmitting and receiving of electromagnetic waves between the circuit of the electromagnetic pen and the antennas or the sensor coils.
Input apparatuses which use the electromagnetic type input technology comprise smart mobile devices (Smart Phone), digitizers or tablets or e-books/green books and are used with electromagnetic pens or styluses.
The circuit of the electromagnetic pen usually comprises an inductor, a capacitor and relative components enclosed in a case. The inductor constituted by a ferrite core winded with a metal coil and the capacitor constitute the circuit to transmit and receive electromagnetic signals with the antennas or sensor coils. The frequency variation of the circuit is achieved via changing the capacitance and the inductance so that the design of the electromagnetic pen can choose either the inductor or capacitor to be variable or adjustable according to the requirement.
The invention provides an electromagnetic pen with electromagnetic and ink writing functions used with an input apparatus.